It really depends on why you’re writing the blog in the first place. If you’re doing it only for the feedback, and the feedback you’re getting isn’t enough for you, then yes; maybe it is time to hang it up.
Personally, I’ve found several good reasons to keep blogging even when I’m not getting much feedback:
1. Memories. I’m in the process of manually backing up my blog for the past five years, as well as scanning, annotating, and posting some zines I wrote from 1991 through 1996. It amazes me how much stuff I’d forgotten – interesting stuff, too! And I have a better memory than most people. A blog is a great way to save memories that might otherwise be lost forever.
2. Connections. Even during the times when I don’t get much feedback, once in a while I get a response that makes it worthwhile. Email from the author of a book I’ve reviewed, or a disk of cool stuff from a friend.
3. Memories for others. This may not apply to you, but many of my journal entries have been about milestones in the life of my son. I’m writing them for him. He’s six now, but when he’s older I think he’ll read those old entries and be glad that they’re there (which is also why I’m backing them up).
4. Writing practice. If you’re interested in writing and perhaps one day getting published, keeping a blog is a good way to get yourself into the habit of writing regularly.
So why do you blog, anyway?